1. Nanomaterials Research Group, School of Chemical Sciences, Universiti Sains Malaysia, USM, 11800 Penang, Malaysia
2. Electronic Materials Research Group, School of Materials & Mineral Resources Engineering, Universiti Sains Malaysia, Nibong Tebal, 14300 Penang, Malaysia
3. School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
4. Department of Materials Science, Faculty of Engineering, Kyushu Institute of Technology, 1-1 Sensui-cho, Tobata-ku, Kitakyushu, Fukuoka 804-8550, Japan
5. Graduate School of Engineering, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511, Japan